Answer:
The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find M as such
In which 
is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the mean subtracted by M. So it is 49.57 - 12.17 = $37.40.
The upper end of the interval is the mean added to M. So it is 49.57 + 12.17 = $61.74.
The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).
Answer:
y+9=21
Step-by-step explanation:
9 more than y equals 21.
9. 9.37, 9.3, 9.219, 9.129
10. 0.101, 0.100, 0.012, 0.001
11. 5.312, 5.231, 5.132, 5.123
12. 62.950, 62.905, 62.833, 62.383
Hope it helps
Answer:
The exponential growth function is 
Step-by-step explanation:
Given: The population of a certain city was 145,380 in 2000 and 219,135 in 2010.
To find: exponential growth function that models the growth of the city
Solution:
The exponential growth function is given by 
Here, P denotes total population after time t
denotes initial population
k denotes rate of growth
t denotes time
As 
,
As 
